The present invention relates generally to surgical instruments and, more particularly, to an acetabular cup installation tool and a method of installing the acetabular cup using the tool.
Total hip replacement is a surgical reconstructive procedure frequently performed by an orthopedic surgeon. It involves replacement of the acetabulum socket in the pelvis of the patient with an acetabular cup and replacement of the femoral neck on the femur of the patient with a prosthesis that has a ball adapted to engage in the acetabular cup.
In the procedure, the acetabulum socket is reamed out by the surgeon to enlarge it to receive the acetabular cup. The cup in effect will constitute a new socket and lining for the patient's acetabulum. The cup is then inserted in the reamed out recess and maneuvered to the proper angular orientation. Insertion and placement of the cup by the surgeon is carried out either by hand or by use of a hand tool that grips the cup.
The reamed out acetabulum which receives the cup is relatively inaccessible and thus it is difficult for the surgeon to see to maneuver the cup by hand into the proper position after insertion so that the cup can be screwed into place. Insertion and placement of the cup by use of a hand tool is preferred over placement by hand. However, most prior art placement tools are complicated, awkward and difficult to use.
One type of prior art positioning device engages the acetabular cup on the outer periphery thereof. A disadvantage to this type of device is that it obscures the vision of the surgeon in placing the cup, and the fact that it engages the cup on the outer periphery may interfere with full insertion of the cup into the socket. Another type of prior art positioner utilizes a vacuum to hold the cup as it is positioned. However, it is difficult to apply sufficient vacuum to securely hold the cup during positioning. Yet a further prior art device utilizes a screw connection between the positioner tool and the cup, but this limits the direction that the cup can be rotated during insertion and complicates the disengagement of the cup after it has been precisely positioned into the desired location in the socket.
Consequently, a need still exists for improvements in a hand tool and method for installing a acetabular cup for hip socket replacement.